Abstract: The invention relates to a method for a user to obtain services from an Instant Message and Presence Service (IMPS) server. The user is identified by a user identification (UserID). An application session is established, through an application client of the user, on the IMPS server. In order to establish the session, an identification code is established in order to be used for the session, and the session is established only if the identification code is not being used for an existing session established by the same user on the same server.

Abstract: The invention discloses a method, system, target terminal device, subject terminal device and computer programs for maintaining and updating data contents in at least one data content server and target terminal device. In one embodiment, a data content change relating to a subject terminal device is detected in a data content server. The data content server transmits an identifier to at least one target terminal device. If the at least one target terminal device has data content corresponding to the received identifier in its memory, it may use it. If such a data content corresponding to the received identifier is not found in its memory, the at least one target terminal device requests the changed data content from the data content server.

Abstract: A presence service is employed to keep track of the kinds of content types that are supported by various subscribing client devices as well as any size limitations for a given content type supported by a given device so that another client device wishing to send a message to a particular other client can consult the presence service before sending the message and determine whether the intended recipient is capable of handling the message. If not, the message is not sent and unnecessary fees for using the messaging service are avoided.

Abstract: The invention relates to a method for a user to obtain services from an Instant Message and Presence Service (IMPS) server. The user is identified by a user identification (UserID). An application session is established, through an application client of the user, on the IMPS server. In order to establish the session, an identification code is established in order to be used for the session, and the session is established only if the identification code is not being used for an existing session established by the same user on the same server.